From time to time there is a need to provide an emergency shelter which provides interim housing for purposes such as disaster relief or for refugees; in some cases for many years of use. If the shelter was stackable and light in weight, many shelter units can be transported to a site by airlift, and perhaps parachuted or simply dropped into a location. Storage is facilitated if the shelters are stackable. The qualities of a shelter include a balance between lightness and cheapness (hence availability) on the one hand, security and protection (such as insulation from wind, rain, snow or extremes of temperature) on the other hand, and always livability.